package DuoTai1.demo2;

public class Computer {
    public void oppenComputer(){
        System.out.println("电脑已经打开");
    }

    public void closeComputer(){
        System.out.println("电脑已经关闭");
    }

//    定义usb
    public void useUSB(USB usb){
        usb.oppen();
        usb.close();
    }
}
